Insulating-joint.



L. McCARTHY.

INSULATING JOINT.

APPLICATION FILED JUNE I. 1914.

1,170,920, Patented Feb. 8, 1916.

/f fir III M 74/1470? fivawfars /%n/ f M 1M; h auza LOUIS MOCARTHY, OF BOSTON, MASSACHUSETTS.

INSULATING-J om T.

Application filed June 1, 1914. Serial N 0. 842,007.

To all whom it may concern:

Be it known that 'I, LOUIS MCCARTHY, a citizen of the United States, residing at Boston, county of Suffolk, State of Massachusetts, have invented a certain new and useful Improvement in Insulating-Joints, of which the following is a specification, reference being had therein to the accompanying drawings.

My invention has for its object a new and improved insulator orinsulating joint which shall be fireproof and which shall have the necessary mechanical strength and resistance to an electric current. Theinsulator described herein has these qualities and is also cheap and convenient to manufacture.

When insulating joints are being installed, it is customary to heat them in a Bunsen flame or torch until they are hot enough to melt gas-fitters wax. When insulators of the ordinary type are treated in this way, the 'insulation is injured or impaired, the end members are loosened and the effectiveness of the joint is practically destroyed without the-damage belng apparent to the workman.

My object, therefore, has been to devise an insulator which can be treated in this manner without having its insulating properties impaired.

Various fireproof compounds which have the necessary electrical resistance for cur-. rents up to -5000 volts are available, but heretofore it has not been found possible to employ these materials successfully because if the joint is constructed to havethe necessary mechanical strength it is found that it is likely to be ruptured electrically, particularly. by the current passing from the proximate faces of the endmembers to the shell or to each other. The insulating joint embodying my invention has the necessary electrical and mechanical strength, and may be made of fireproof material. It is also very cheap to manufacture on ,account of the cheapness of the main body of insulating material.

The novel process by which my improved insulator is constructed forms the subject matter of a companion application filed by me on June 1, 1914, Ser. No. 842,008 to which reference may be had.

The invention will be fully understood by reference to the following description taken in connection with the accompanying Specification of Letters Patent.

Patented Feb. 8, 1916.

drawings and the novel features thereof be particularly pointed out and clearly de-' fined 1n the claim at the close'of this specification. In the draWingaIFigur'e 1 is a side elevation ofan insulati gjoint embodying my invention. .Fig. .2 is a vertical section of, the joint.

Referring now to the drawings, at 11 and 12, are indicated two end members tapped as shown at 13 and 14 for connection with a gas pipe or stud and the fixture. These end members are providedat 15'and16 respectively with. flanges preferably of irregular shape to afford greater adhesion to the from each other by a washer 21 of ins'ulat-' ing material. This washer is composed of, superposed leaves of natural ni-i'ca preferably united by a suitable insulating adhesive and effectually prevents the current jumping from one end member to the other. Tie end members are preferably cut away as shown at 22, and the washer preferably projects as shown at 23 into the annular space thus formed. This construction is found to offer greater resistance to the elec L tric current and to prevent it from jumping from one end member to the other through the bore in case dustor other foreign niaterial accumulates at this point,

The interior of the shell 18 is lined with a tubular lining 24 of insulating niaterial.

This lining is composed of leaves of natural.

mica superposed upon each other and secured together with a suitable insulating adhesive as for instance liquid shellac to form a flat sheet which is rolled upon a mandrel to form the tube 24. Thistube 24 is shaped to conform exactly to the shape of the inwhen-the coupling is,

terior of the shell between the inturned flanges 19 and 20. If the shell is of non cylindricaLform the lining tube is of corre sponding shape.

Molded about the flanges of the end members 11 and 12 are masses as of insulating material, these being designated 25 and 26.

the tube and shell. areof non-circular shape, the blocks of insulating material will be given a corresponding shape.

- After the-masses of'nsulation 25 and 26 have been molded about the end members, and while this insulation is still capable of being .formed, the parts are assembled within the shell and the whole subjected to heav pressure in suitableidies WlllCll form the anges on the shell. The said pressure drives the insulating material into every irregularity, and compacts the insulation and forms the whole into a unitary structure. After the shell has been shaped as described, the entire insulator is vulcanized or baked to set and harden the masses of insulating material 25 and 26. This also has the efiect of softening the insulating adhesive contained in the lining tube 24 and results in producing a more perfect union between the various parts of the insulator, thereby materially increasing the electrical resistance of the finished article. This baking process also expels the moisture from the masses of insulating material 25 and 26.

What I claim is:

The improved insulator comprising flanged masses of insulating material and securing the whole together.

- In testimon whereof I ailix my signature, in presence 0 two witnesses.

' LOUIS MCCARTHY. Witnesses:

J. ETHEL Seaman,

GARDNER W. PnoU'rY. 

